Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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  • Article
    Citation - WoS: 19
    Citation - Scopus: 22
    Enhanced Methylene Blue Removal Efficiency of Tio2 Embedded Porous Glass
    (Elsevier Ltd., 2021) Ertuş, E.Burak; Vakıfahmetoğlu, Çekdar; Öztürk, Abdullah
    A porous glass (PG) embedded with titanium dioxide (TiO2) was produced via impregnation of the PG with Titanium (IV) Isopropoxide solution followed by crystallization. N2 sorption analyses revealed that the specific surface area (SSA) and total pore volume of the PG reached to 358 m2/g and 0.370 cm3/g, respectively. The adsorption capacity of methylene blue (MB) for the glasses was measured in the dark, instead the photocatalytic MB removal efficiency was evaluated by the degradation of MB under UV light illumination using a UV–vis spectrometer. The MB removal efficiency of the TiO2 synthesized anatase powder was only 32.3 % whereas, for TiO2 embedded PG (TiPG) it was 91.6 %, and nearly complete (> 99 %) efficacy was achieved for TiO2 embedded alkaline leached PG (TiPG-AL) under UV illumination 3 h period. Better MB removal efficiency was attributed to high SSA and dispersion of nano size anatase TiO2 crystallites within the porous structure. © 2020 Elsevier Ltd
  • Article
    Citation - WoS: 11
    Citation - Scopus: 13
    Production and Properties of Phase Separated Porous Glass
    (Elsevier, 2020) Ertuş, E. Burak; Ahmetoğlu, Çekdar Vakıf; Öztürk, Abdullah
    A sodium borosilicate glass (SBG) was produced by conventional melt-quenching. As cast glass was heat treated to induce phase separation (SBG-HT), followed by acid leaching with HCl to dissolve one of the separated phases; i.e. alkali rich borate phase, so that a porous glass (PG) was obtained. In order to alter the pore structure, produced PG was subsequently alkali (NaOH) leached or alternatively heat treated. The samples were characterized by techniques including XRD, SEM, N-2 adsorption/desorption. The total pore volume for PG was found to be 0.314 cm(3)/g, reached to 0.370 cm(3)/g by alkali leaching, instead decreased to 0.227 cm(3)/g by heat treatment. The microhardness and tribological properties of SBG-HT and all PGs were evaluated by Vickers hardness and by pin on disk tribometer. For all PGs the microhardness values were lower, instead the wear rates were higher than that of the parent SBG-HT.
  • Article
    Citation - WoS: 57
    Citation - Scopus: 69
    Leaching Behavior of Selected Trace Elements in Coal Fly Ash Samples From Yenikoy Coal-Fired Power Plants
    (Elsevier Ltd., 2012) Akar, Gül; Polat, Mehmet; Galecki, Greg; Üner, İpekoğlu
    Short-term leaching test results of alkaline fly ash from Yenikoy coal-fired power plant were reported in this paper. ASTM D-3987-85 and TCLP-1311 test methods were applied to determine leaching behavior of selected elements namely, Fe, Ca, Cu, Co, Cd, Mn, Ni, Pb Zn, and Cr (VI) at different particle size fractions and test conditions. Chemical, mineralogical and morphological characterizations of ash samples were also performed using chemical, XRD and SEM-EDS analysis methods. The results showed that CaO dominates in the Yenikoy fly ash sample which directly affects the mobility of trace elements by determining the pH of the leaching medium. Higher mobility values of Cd, Co Cu, Pb, Ni and Zn elements were observed for TCLP-1311 procedure. The concentration of these elements in leachates showed a tendency to increase by decreasing particle size. Overall results suggested that the amount of the selected elements in the final leachates of both tests was lower than the limit values of landfill regulations except Cr (VI).
  • Article
    Citation - WoS: 29
    Citation - Scopus: 38
    Encapsulating Fly Ash and Acidic Process Waste Water in Brick Structure
    (Elsevier Ltd., 2010) Köseoğlu, K.; Polat, Mehmet; Polat, Hürriyet
    Fly ash contains metals such as cadmium, iron, lead, aluminum and zinc in its structure in appreciable amounts. These metals can leach out into surface and ground waters if fly ash is not properly disposed of. A similar problem also exists for acidic process waste waters discharged by numerous industries. The purpose of this study was to utilize such wastes as additives in the production of construction quality bricks for the purpose of waste elimination. The bricks produced were subjected to flexural strength and water retention capacity tests along with heavy metal leaching experiments in order to determine the applicability of the procedure and the best possible recipes. This paper summarizes the results obtained in these tests along with the possible mechanisms involved in stabilizing the two wastes in the brick structure. © 2009 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 61
    Citation - Scopus: 69
    Leaching Characteristics of Fly Ash From Fluidized Bed Combustion Thermal Power Plant: Case Study: Çan (çanakkale-Turkey)
    (Elsevier Ltd., 2010) Baba, Alper; Gürdal, Gülbin; Şengünalp, Fatma
    It is known that the concentration of elements of fly ash varies due to the used-coal and the used-lime qualities varying in different periods. In the Çan Thermal Power Plant (CTPP) located at northwestern Turkey, Çan (Çanakkale) basin coals, which are classified as lignite to sub-bituminous C coal with high total sulphur (0.4-12.22%) and a broad range of ash contents (3.2-44.6%) are mainly used. Performed studies reveal that some toxic elements exit in the coal, including As, U and V. Also, while the As, Cu, Co and Hg contents in coal increases, the sulphur contents in coal also increase. Additionally, trace elements that have inorganic compounds in coal are mobilized into air during the combustion process. This poses a big risk for human health and keeping the environment when Çan Basins low quality lignite is burned, it's the fly ash that contains several toxic elements which can leach out and contaminate the water resources. In this study, toxicity tests were conducted on the fly ash samples that were obtained from the fluidized bed combustion of Çan Thermal Power Plant. The results showed that water temperature, pH and the quality of the limestone used were the most important factors affecting the leaching properties. Concentration of some toxic elements found in the fly ash, such as; As, Cd, Cr, Pb, Se and Zn were analyzed. Concentration richness of some heavy metals were attributed to the increase of water temperature, especially when pH is lower than 5. At pH=5 value, there is no clear explanation of each heavy metal presence in the fly ash from fluidized bed combustion thermal power plant. © 2010 Elsevier B.V. All rights reserved.